Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so 'Read-only listing' repeats structured data. The genuinely additive context is the integration prerequisite (Settings - Integrations) and the flow_set consumption path, which go beyond annotations but leave return format/shape unstated.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences, purpose and the sync behavior front-loaded. The final sentence mixes setup and downstream usage compactly without waste, though it could be split.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a zero-required-param read listing with no output schema, the description covers what the images are, how to refresh them, and the prerequisite connection. Return value shape is unspecified but low-risk for a simple list.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Only one parameter and schema coverage is 100%, with the schema describing 'sync' as a re-pull. The description's 'Pass sync: true to re-pull from Hyperise first' adds the ordering hint but little beyond the schema, matching the baseline 3.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States the resource precisely ('personalised-image templates from a connected Hyperise account') and the title supplies the listing verb. It is distinguishable from sibling list tools like template_list or placeholder_list by naming the Hyperise source, though the verb itself is only implied.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explains the intended context ('for use in email and message copy') and the downstream mechanism ('referencing it in copy you pass to flow_set'), plus when to set sync. No explicit when-not-to-use or alternative named, so it stops short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.